From a828d56aebc0735676be23734cccf31e279c0d1b Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@unimore.it>
Date: Mon, 8 Dec 2014 16:04:25 +0100
Subject: [PATCH 1/3] block: cgroups, kconfig, build bits for BFQ-v7r7-3.19

Update Kconfig.iosched and do the related Makefile changes to include
kernel configuration options for BFQ. Also add the bfqio controller
to the cgroups subsystem.

Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
---
 block/Kconfig.iosched         | 32 ++++++++++++++++++++++++++++++++
 block/Makefile                |  1 +
 include/linux/cgroup_subsys.h |  4 ++++
 3 files changed, 37 insertions(+)

diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index 421bef9..0ee5f0f 100644
--- a/block/Kconfig.iosched
+++ b/block/Kconfig.iosched
@@ -39,6 +39,27 @@ config CFQ_GROUP_IOSCHED
 	---help---
 	  Enable group IO scheduling in CFQ.
 
+config IOSCHED_BFQ
+	tristate "BFQ I/O scheduler"
+	default n
+	---help---
+	  The BFQ I/O scheduler tries to distribute bandwidth among
+	  all processes according to their weights.
+	  It aims at distributing the bandwidth as desired, independently of
+	  the disk parameters and with any workload. It also tries to
+	  guarantee low latency to interactive and soft real-time
+	  applications. If compiled built-in (saying Y here), BFQ can
+	  be configured to support hierarchical scheduling.
+
+config CGROUP_BFQIO
+	bool "BFQ hierarchical scheduling support"
+	depends on CGROUPS && IOSCHED_BFQ=y
+	default n
+	---help---
+	  Enable hierarchical scheduling in BFQ, using the cgroups
+	  filesystem interface.  The name of the subsystem will be
+	  bfqio.
+
 choice
 	prompt "Default I/O scheduler"
 	default DEFAULT_CFQ
@@ -52,6 +73,16 @@ choice
 	config DEFAULT_CFQ
 		bool "CFQ" if IOSCHED_CFQ=y
 
+	config DEFAULT_BFQ
+		bool "BFQ" if IOSCHED_BFQ=y
+		help
+		  Selects BFQ as the default I/O scheduler which will be
+		  used by default for all block devices.
+		  The BFQ I/O scheduler aims at distributing the bandwidth
+		  as desired, independently of the disk parameters and with
+		  any workload. It also tries to guarantee low latency to
+		  interactive and soft real-time applications.
+
 	config DEFAULT_NOOP
 		bool "No-op"
 
@@ -61,6 +92,7 @@ config DEFAULT_IOSCHED
 	string
 	default "deadline" if DEFAULT_DEADLINE
 	default "cfq" if DEFAULT_CFQ
+	default "bfq" if DEFAULT_BFQ
 	default "noop" if DEFAULT_NOOP
 
 endmenu
diff --git a/block/Makefile b/block/Makefile
index 00ecc97..1ed86d5 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_BLK_DEV_THROTTLING)	+= blk-throttle.o
 obj-$(CONFIG_IOSCHED_NOOP)	+= noop-iosched.o
 obj-$(CONFIG_IOSCHED_DEADLINE)	+= deadline-iosched.o
 obj-$(CONFIG_IOSCHED_CFQ)	+= cfq-iosched.o
+obj-$(CONFIG_IOSCHED_BFQ)	+= bfq-iosched.o
 
 obj-$(CONFIG_BLOCK_COMPAT)	+= compat_ioctl.o
 obj-$(CONFIG_BLK_CMDLINE_PARSER)	+= cmdline-parser.o
diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index 98c4f9b..13b010d 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -35,6 +35,10 @@ SUBSYS(net_cls)
 SUBSYS(blkio)
 #endif
 
+#if IS_ENABLED(CONFIG_CGROUP_BFQIO)
+SUBSYS(bfqio)
+#endif
+
 #if IS_ENABLED(CONFIG_CGROUP_PERF)
 SUBSYS(perf_event)
 #endif
-- 
2.3.0

